Hondata

Hello everyone,

I am new on here and was hoping to confirm my understanding of my data logs. I am new to engine tuning, but I am not new to how engines run and perform. I have a 2007 Civic Si.

I made some changes to my setup and it seemed that the base map could use a change as well.

Previous setup: AEM SRI and 3" Catback. Stock header and CAT running the AEM SRI base map

New setup: AEM SRI and 3" Catback. DC Sports header and stock CAT running the AEM SRI base and AEM SRI, race header, highflow cat, stock catback. Base maps

Thoughts: Even though I still have the stock CAT I should have similar exhaust flow since I have the 3" catback and not the factory system.

Data logs:
"Burrows FG2 Log 2"
The AEM SRI base map with my new mods seems to have way more erratic AFR and also has more knock backing off timing. Cam angle also isn't as advanced.

"Burrows FG2 SRIHEADERBaseThrottle"
The race header base map has much more stable AFR and about half the amount of knock coming into play. The cam angle is more aggressive across the board and it looks like I have enough air flow to support it since AFR readings are ok. Short fuel trim has a crazy spike, but I don't think that is an issue.

Are these statements above correct or I am I off somewhere?

I also want to make sure that I am currently running the safest base map and if I need to worry about any major changes. Thanks for any input.

Something is wrong. You are getting a 45% fuel trim with one datalog, and then between datalog there is a big difference in airflow, and then one has a 12ms injector duration at the same point the other datalog has a 16 ms injector duration. There's knock, with the second datalog showing the knock control maxed out. I don't think it is worth trying to work out what calibration is better when there is a such a big different in fuel trim and fueling.

I'd go back to 'factory settings' and then try to work on why the short term trim / lambda is nonsensical.

Glad I touched base here, Thanks for the response. That is something I haven't tried yet. I'll try data logging on a factory setting and see what I get. The car does have 140K on it, so maybe something else is going on. I'll post up a a factory data log once I have chance to do it.

I had a chance today to flip back to the factory calibration and do a few logs.

1st pull I didn't really get the same result as the previous ones with S trim. Logs 2 and 3 I did get similar S trim readings as the other calibrations. Log 3 was even with different fuel.

I did a 4th log which was just a steady log around the problem RPM. Had a similar reading once I was WOT.

What would you suggest next?

Put the intake back to stock. If that doesn't work, replace the AFM. It might be the o2 sensor, but normally they just don't work at all when bad.

Thank you for the suggestion. Unfortunately I don't have the factory air box, but I'm going to try cleaning the MAF and doing a few other things. It's probably due for a little tune up, and I don't know how old or what kind of spark plugs are in it.

I did a little service on the car. New Spark plugs, cleaned the MAF, intake tube and throttle body. I wasn't sure of spark plug age or type. Turn out they were Denso and I replaced them with Laser IR NGK.

Seems like I am getting better readings now. OEM tune seemed more consistent, so I threw the other base map at it as well to see what it would do.

Thoughts?

I noticed on your most recent 3rd gear pull that the car is in closed loop from the start to about 3900RPM.
To my knowledge, shouldn't the car be in open loop at all times in WOT conditions?

A/F R is almost consistent from 2000RPM to redline. Small adjustments will make it more level.
It's averaging around 13.2-13.5 (Lambda 0.90-0.92).
Personally, I like to tune to 12.5 (Lambda 0.85) at WOT so in my eyes you're a little lean.
No knocking based off this log though!...and that's with 29-30 degrees of timing in the top end which to my understanding is pretty aggressive.

Note: I'm assuming you're running pump gas so I'm basing my numbers around that.